USB Host Controller Registers
14-11
Universal Serial Bus Host
Table 14–3. HC Operating Mode Register (HcControl) (Continued)
Bit
Reset
Value
Type
Description
Value
Name
7–6
HCFS
Host controller functional state:
R/W
00
00
USBReset
01
USBResume
10
USBOperational
11
USBSuspend
A transition to USBOperational causes SOF generation
to begin in 1 ms. The USB host controller may
automatically transition from USBSuspend to
USBResume if a downstream resume is received. The
USB host controller enters USBSuspend after a
software reset. The USB host controller enters
USBReset after a hardware reset. The USBReset state
resets the root hub and causes downstream signaling
of USBReset.
5
BLE
Bulk list enable:
R/W
0
0
Bulk ED list not processed in the next 1-ms frame. Host
controller driver can modify the list. If driver removes
the ED pointed to by the HcBulkCurrentED from the ED
list, it must update HcBulk-CurrentED to point to an ED
still on the list before it reenables the bulk list.
1
Enables processing of bulk ED List. HcBulkHeadED
must be 0 or point to a valid ED before setting this bit.
HcBulkCurrentED must point to a valid ED or be 0
before setting this bit.
4
CLE
Control list enable:
R/W
0
0
Control ED list is not processed in the next 1-ms frame.
Host controller driver may modify the control ED list. If
driver removes the ED pointed to bythe
HcControlCurrentED from the ED list, it must
updateHcControlCurrentED to point to an ED still on
the list before it reenables the control list.
1
Enables processing of the control ED list.
HcControlHeadED must be 0 or point to a valid ED
before setting this bit. HcControlCurrentED must be 0
or point to a valid ED before setting this bit